Some people hold that the more conservative the world becomes, ______ have old furniture, old houses and old paintings.

A. the smarter is to


B. the smarter it is to
C. is it the smarter so

D. is one to the smarter

读图回答下列问题。

地震波的传播速度与地球的内部圈层的划分图

三个圈层名称：A是（），B是（），C是（）。